As others have noted, it is something non-symmetric about your plane. If it was 10-20 degrees bank, I would not worry too much. However, with 40 degrees opposite bank, something is way off.
Look first for something not statically symmetric. A wing twisted, uneven sanding, etc., as others have mentioned.
Then look for something dynamic. Measure your flap stiffness at several points along the span, on each side. They should agree. (We have balsa flaps, so uneven sanding or uneven grain in the wood can cause this). Carefully feel the twist stiffness of the leading edge area, both winds need to have similar stiffness. Carefully review the tip bending (outside the flaps). One typical method of trimming to eliminate bunting is to bend both tip TE's up a bit, which at high speed levers the whole wing to twist to more positive incidence. A little goes a long way. So if your left tip TE is up a little higher than the left wing, then at launch speeds the left wing is going to higher incidence and rolling the plane to the right. It seems backwards, but watch some of Josh's videos, he explains it nicely. It is possible you bent the left TE up to try to cancel right roll (thinking ailerons), but actually made it worse!